.TH std::experimental::nullopt_t 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::experimental::nullopt_t \- std::experimental::nullopt_t

.SH Synopsis
   Defined in header <experimental/optional>
   struct nullopt_t;                          (library fundamentals TS)

   std::experimental::nullopt_t is an empty class type used to indicate optional type
   with uninitialized state. In particular, std::experimental::optional has a
   constructor with nullopt_t as a single argument, which creates an optional that does
   not contain a value.

   std::experimental::nullopt_t must be a LiteralType and cannot have a default
   constructor.

   It must have a constexpr constructor that takes some implementation-defined literal
   type.

.SH Notes

   nullopt_t is not DefaultConstructible to support both op = {}; and op = nullopt; as
   the syntax for disengaging an optional object.

   A possible implementation of this class is

 struct nullopt_t
 {
     constexpr nullopt_t(int) {}
 };

.SH See also

   nullopt an object of type nullopt_t
   \fI(C++17)\fP (constant)

.SH Category:
     * Noindexed pages
